The .tiff format is not well supported in ImageMagick according to the support documentation for the program so it is unlikely to work as expected, try any other supported image format and you should be able to achieve the results you want.
The TIFF format is the propriety format for PhotoShop. However it is
so bloated with features, and has been modified by just about every
application that has cared to use it, that no program, not even
photoshop can handle ALL its variations. Photoshop however has the
best chance at reading it.
I would steer clear of the TIFF image file format unless you are
specifically working with photoshop, or the application accepts no
other, better defined, image file format.
I don't use the TIFF image file format, or Photoshop. If you use
this format with IM extensively, perhaps you would like to submit
your findings to me, to include here. That way you can help your
fellow TIFF users.
Whether a specific software package can read a TIFF, all you can do
is try it and see. That is the problem with this format.